Blood loss is a serious complication of open-heart and other major surgeries. Cardiac surgery patients account for a significant proportion of transfused donor blood. Blood transfusion carries risks of disease transmission and adverse reactions. In addition, donor blood is expensive, and demand often exceeds supply.
Pharmacological and other methods for reducing blood loss and the resultant need for transfusion have been described (reviewed by Scott et al., Ann. Thorac. Surg. 50: 843-851, 1990). Prostacyclin and desmopressin acetate have been tested, but results with desmopressin acetate have been inconclusive, and neither of these agents has been able to eliminate the need for postoperative transfusion.
Bovine aprotinin has been reported as being effective in reducing perioperative blood loss (Royston et al., Lancet ii: 1289-1291, 1987; Dietrich et al., Thorac. Cardiovasc. Surq. 37: 92-98, 1989; Fraedrich et al., Thorac. Cardiovasc. Surg. 37: 89-91, 1989), but adverse effects, including hypotension and flushing (Bohrer et al., Anaesthesia 45: 853-854, 1990) and allergic reaction (Dietrich et al., ibid.) have been reported. The use of aprotinin in patients previously exposed to it is not recommended (Dietrich et al., ibid.). The use of blood-derived aprotinin does not eliminate the risk of transmission of viral diseases. Moreover, aprotinin has not yet been approved for use in the United States.
There remains a need in the art for a reliable and widely applicable method of reducing blood loss during and after surgery. In particular, there is a need for a method that is non-immunogenic and does not rely on blood-derived products. There is also a need for a method that does not produce the adverse side effects seen with aprotinin therapy. The present invention fulfills this need by providing an improved method of reducing perioperative blood loss.